June 2, 2011: I have mentioned John Napier of Edinburgh
before, a
Scottish nobleman and mathematician of interest. His last book from
1617 was called Rhabdologiae, in latin meaning the teaching of rods as
one of his inventions was a calculation system based on numbers
systematically written on small rods, or bones as they also were called.
My own set is pictured here, calculating an example given by Napier
himself , the year 1615 multiplied with 365. The rods are cut from
sticks of birchwood used here i Norway for preparing "pinnekjøtt" , a
traditional christmas meal of salted and dried sheep meat where you
first pour a bit of water into a pot, then make a stick bed and over
put the dried meat. Let it boil for several hours, and you have a meal
for a king.
Uptil christmas the birchwood sticks are sold in bundles of 20. They
are cut in size 1x1 cm and app. 15 cm. long. If you cut ten sticks to
10 cm. and glue the templates (should fit) from this A4 pdf onto, you
are ready to go. Could make a present for uncle Peter, especially if
you have learned to calculate with the bones first!.
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The white rods on the image are sticks with drafts of templates glued onto.Inspecting the templates will show John Napier flipped the face of the numbers on two of the sides, perhaps using special hand movements in his calculations. Templates as images for scaling to fit other stick sizes here and extracts of different sources in the public domain with examples here. |